We use cookies to allow us and selected partners to improve your experience and our advertising. By continuing to browse you consent to our use of cookies as per our policy which also explains how to change your preferences.

How we test disposable nappies

By Lisa Galliers

Are Pampers the perfect nappy? We've pitted the brand leaders size 4 offerings against the other size 4 disposable nappies you may find in the shops near you. Find out who comes top in our tests.

Put us to the test

Our Test Labs compare features and prices on a range of products. Try Which? to unlock our reviews. You'll instantly be able to compare our test scores, so you can make sure you don't get stuck with a Don't Buy.

A baby needs changing frequently during the day, and sometimes overnight, too, so the last thing a sleep-deprived parent wants is a nappy that leaks. 

We've independently tested size 4 nappies from the brand leaders, Pampers, against a range of supermarket and chemist own-brand offerings, of the same size, to reveal which nappies leak the least, and which ones lock moisture into the core and away from your baby's delicate bottom. Find who makes the perfect nappy. 

Our reviews answer the most crucial questions about disposable nappies: 

  • Which nappies absorb the most?
  • Which nappies will help keep my baby's bum dry?
  • Which nappies won't leak?
  • Which nappies are the easiest to use? 
  • Which nappies are most recommended by parents who use them?

Find out which disposable nappies are the ones that won't let you down in our disposable nappy reviews.

Which disposable nappies absorb the most? 

Nappy changing can be a chore, so a decent nappy can help reduce the number of nappy accidents you'll need to deal with by quickly soaking up your baby's excretions. 

Our lab experts test each nappy in exactly the same way. Each is filled with the same measured amount of synthetic urine, gushed into the core of the nappy and allowed to soak in. This is repeated four times. This represents a nappy being on during the day and overnight, filling with liquid. 

Our lab experts measure the rate the nappy absorbs the fluid the first time it hits a fresh nappy, and after each subsequent gush, noting how much the rate reduces as the nappy fills up. A good nappy should be able to absorb wetness quickly regardless of whether it's the first time or the fourth time. 

But, it's not just about how much a nappy can soak up, so read on. 

33%Parents or carers we surveyed currently using Pampers nappies.

Which disposable nappies leak?

A nappy may well be able to soak up a lot of wetness, but to be a decent nappy it needs to prevent the wetness from reaching the outside. That means no soggy babygrows to sort out over Sunday lunch, or damp bedsheets to deal with at dawn.  

Once each nappy is fully filled with fluid, our lab experts test to see how well the nappy keeps the fluid inside, or whether any of it leaks out, and where that wetness goes. 


21%Parents or carers we surveyed are currently using Aldi Mamia nappies.

Which? disposable nappies will help keep wetness away from my baby's bottom? 

The third key component of an effective nappy is will it keep the wetness away from your baby's skin.

Our experts place filter paper on top of a fully fluid-loaded nappy and weigh it down to see how much wetness comes back out. This is designed to replicate your baby sitting on top of a nappy it's been in for a while, overnight for example. 

The best nappies will soak up fluid quickly, have effective leakage cuffs so it won't escape, but will also keep liquid locked away in it's core and not let it back out onto your baby's skin. 

Some babies, especially those with delicate skin, can develop nappy rash if they're left in a nappy that lets wetness back onto the skin. The best nappies don't let this happen.  

82%Highest scoring brand in our 2018 nappy survey.

What do parents and carers think of the nappy brands? 

Lab testing is a great way to measure and test absorbancy, wetness and leaks in a scientific way, but we know that all babies are different, so we haven't just relied on lab testing to work out which nappies are winners. 

We asked 3,445 parents and carers to tell us about the brand of nappies they use the most and ask them to rate comfort, fit, easy of use and value for money. We also asked how satisfied they were and if they'd recommend the brand currently being used.

We combined both of these to bring you an overall total test score for each disposable nappy brand in our testing.  

Should I buy it? 

The results from all of the tests listed above, as well as the results of our survey of 3,445 parents and carers, are combined to make the final overall score for each disposable nappy we review. Because we know what's most important to you, some elements are more important than others, so carry different weights:

  • 50%...lab tests (Absorbancy, leakage, re-wet, fastenings)
  • 50%...parent survey (Customer score, comfort, fit, value for money)

A Best Buy disposable nappy needs to score 74% or above, and any disposable nappy scoring 45% or less will instantly become a Don't Buy


Related products

See all nappies